Describe and explain how the thermal stabilities of the carbonates of the Group $2$ elements vary.
Suggest and explain why sodium carbonate is more resistant to heat than magnesium carbonate.
Write an equation showing the decomposition of potassium hydrogencarbonate, $\text{KHCO}_3$.
Predict which of $\text{NaHCO}_3$ or $\text{KHCO}_3$ will decompose at the lower temperature. Explain your answer.
Use the data in the table below, together with relevant values from the Data Booklet, to calculate the lattice energy, $\Delta H^{\circ}_{\text{latt}}$, of potassium oxide, $\text{K}_2\text{O(s)}$.
State whether the lattice energy of $\text{Na}_2\text{O}$ would be more negative, less negative or the same as that of $\text{K}_2\text{O}$. Give reasons for your answer.